June, 1902.] 



KNOWLEDGE 



127 



tht'v are hatcheil know well the value of Iviusj flat ami 

 keejiiDg as still as stones. My frieud afterwards found a 

 lirooJ on another marsh, but these he failed to catch. In 

 e;u-b case the male bird was evidently attendiu^jj to the 

 youui; as the female was found at some considerable 

 distance. These youuj^ jrodwits were only a few days old, 

 and were beautifully clothed with soft down. They were 

 ijreat prizes, and, as fur as I know, were the first youni,' in 

 down of the l)ar-tailed godwit to lie obtained, although 

 Mr. H. L. Popham has told me that he had seen them on 

 the Yeuesi in Siberia but had been unable to secure any. 



The dusky or spotted redshanks whicli we discovered on 

 several marshes were an even greater find than the godwits, 

 because since the days of Wolley, fifty years ago, our 

 knowledge of their breeding haunts has scarcely increased. 

 Unfortunately, however, we were unable to discover either 

 eggs or young of these birds notwithstanding hotirs of 

 watching and searching. One day I watched a pair for 

 two hours without success, so wary were the birds. When 

 I was in view they flew wildly about uttering an incessant 

 rattling alarm note. Then when I got well hidden they 

 kept ijuiet, and ray hopes of their visiting the nest or young 

 revived. I waited. Meanwhile the mosquitoes gathered in 

 thicker and thicker swarms. My veil getting disarranged 

 touched the back of my neck, and immediately a cluster of 

 mosijuitoes settled on the place. A slight exclamation and 

 an incautious movement were impossible to jjrevcnt, and 

 the ever-watchful redshanks saw me and began their fuss 

 and clamour again. I had to change my hiding-place and 

 wait again, but the mosquitoes and the redshanks always 

 got the best of it in the end, and at last I came to the 

 conclusion that my patience was insufficient for the task. 



The majority of wading birds have a larger and richer 

 plumage in summer than in winter, and these redshanks 

 were of a very handsome sooty-black colour spotted with 

 white. Their beaks were dark, but their legs were of a 

 neh crimson, which looked very bright against their black 

 breasts. 



To find these two species in their breeding haunts was 

 especially interesting to us, because both birds visit the 

 shores of England on their migrations in spring and 

 autumn. 



VEGETABLE MIMICRY AND 

 HOMOMORPHISM.-III. 



By Rev. Alex. S. Wilson, m.a., b.sc. 



Quite a number of flowers have distinctly mimetic 

 odoui's. It can hardly be doubted, for example, that 

 the ofiFensive smell of the carrion flowers Siapelia, 

 Aristolochia, Aru7/i, Eafflesia, and others, is more effective 

 in promoting cross-fertilisation because of its resemblance 

 to the odour of putrid meat. So completely are the 

 flesh flies deceived that they often deposit their eggs 

 on the petals of caiTion flowers. 



FtBtid odours occur in Bryonia, Helleborus, Geranium, 

 Stachys, Ballota, Iris, and other genera. The odours of 

 others have a curious resemblance to the smells emitted 

 by certain animals. Hypericum hircinum and Orchis 

 hirciria are bad smelling flowers with an t)diiur 

 lesembling that of the goat; Goriandrum sativum has 

 the foetid smell of bugs, while the hemlock, again, emits 

 a strong odour of mice. Along with these may be 

 mentioned Adnra, the musk orchis, the grape hyacinth 

 and other musky scented flowers. 



The resemblance in smell between these flowers and 

 the secretion formed in the scent glands of the musk ox 

 and other animals is, to say the least, a remarkable 

 coincidence. Possibly flies which accompany cattle may 



bo attracted by smells of this description. Very curious 

 also is the vinous smell of (h'liaiitlu'. and the brandy-like 

 aroma of tho yellow water lily Nuphur, hence called the 

 brandy bottle. Ethereal oils exhaled by plants while 

 attractive to some animals seem to repel others; the 

 scents of sweet-smelling flowers such as Daphne, Thymus, 

 Marjoram, Melilotus, and Gymnademia, though grateful 

 to bees and buttci-flies, appear to be distasteful to 

 niminants. Kemer states that in general the latter 

 avoid all blossoms; even caterpillars do not readily 

 attack the petals of their food plants. Odour may there- 

 fore bo protective or attractive or it may bo of use in 

 both ways. Tho same remark applies to colour, which 

 may serve either to attract or repel ; the richly- 

 vai'iegat-ed leaves of the Indian nettles — species of 

 CoUeus — and tho tinted foliage of Bcfjonia and Geranium 

 may possibly escape injury on account of the general 

 resemblance to coloured blossoms. Instances in which 

 one plant resembles another in smell are not very com- 

 mon in the flowering class, though cases do occur like 

 the garlic mustard and apple-scented Salvia. Resembling 

 odours are much more frequent among fungi. 



Characteristic examples of homomorphism are seen in 

 the resemblances which many species of Euphorbia 

 present to the Cactus tribe and in tho pollen-masses of 

 the Oixhids and Asclepias. In Britain the order 

 Euphorbiaceae is represented by the box, dog's-mercuiy 

 and the sun-spurges, but many foreign species have quite 

 a different appearance and agree with the Cacti in their 



Fio. 10. — Cactus and Eupliorbia. 



aborted leaves and green succulent stems. The globular, 

 columnar, and angular forms give to both a peculiar 

 aspect by which they are broadly distinguished from all 

 other vegetable types; and yet in systematic position 

 these two orders stand far apart. The nearest affinities 

 of the Euphorbia; are with the Urticaceae and other 

 orders having incomplete flowers, while the nearest allies 

 of the Cacti are the Cucurbitaceae and other calycifloral 

 orders. Succulent stemmed plants of this description 

 are specially adapted to an arid climate, and it is not 

 uni-easonable to suppose that the similarity between the 

 Euphorbiae and Cacti results from the long-continued 

 ;:ction of similar external conditions upon similarly 

 endowed tissues. 



Sir W. T. Thiselton Dyer, in a paper on " Mimicry in 

 Plants" (British Association, 1871), adduces as examples 

 of homomorphism, or as he terms it, homoplasm, a 

 climbing composite of South America, Mutesia specinsa, 

 having the leguminous habit and closely resembling the 

 European Lalhyrus maritima; three ferns, natives of 

 different parts of the world, which are indistinguishable 

 in the barren state; and a species of Veronica in New 

 Zealand; the latter so resembles a coniferous plant that 

 it misled Sir W. Hooker. 



